where Fbase is the fuel consumption of each ship (see table on next section), distance is defined in this page and speed is the percentage of flight time the ship will be moving (chosen by the player on the fleet screen).
Because deuterium fills space, the fuel must be stored on cargo, decreasing the total Cargo capacity of the fleet.
Since in space the ship does not waste fuel, the fuel is always used on the beginning of the flight, when the ship gains speed. This is implemented on the game: once a fleet is launched, the fuel is completely consumed: even if the fleet is recalled right away, the fuel will still be all used.
* Small Cargo Ships start out with a combustion engine. Once Level 5 Impulse Drive is researched, all Small Cargo Ships are automatically upgraded to Impulse engines and take advantage of the faster speed, but also get higher fuel costs.
* Bombers start out with a impulse engine. Once Level 8 Hyperspace Drive is researched, all Bombers are automatically upgraded to Hyperspace engines and take advantage of the faster speed.
In next figure a graphical representation of these values is made.